Dentures have been manufactured for centuries to replace all or part of an individual's dentition. Dentures have been manufactured by molding the denture from casts made of the patient's edentulous or partially edentulous ridges. The manufacturing process may begin with a preliminary impression of the patient's mouth, which is usually done in silicone or alginate. This impression may be used to prepare a diagnostic cast. While making the impression, the dentist applies pressure to the soft tissues to simulate biting force and extends the borders of the mold to adjacent toothless areas to allow the dentures to better adapt to the gums. A final cast may then be formed from gypsum based on the diagnostic cast. The final cast may be filled or “waxed up” to form the denture. The denture teeth will be set in the wax. The cast with the waxed denture will be placed in a mold and injected or packed with acrylic. Once the resin has cured, the cast may be broken apart and the denture may be removed.
More recently, dentures have been manufactured by machining a void in a block of denture base material formed to match the contour of natural teeth as arranged on a maxilla or on a mandible; filling the void with a synthetic tooth material; removing a portion of the synthetic tooth material; and potentially filling the void and removing a portion of material a second time in order to create denture having teeth made of one or potentially two or more layers.
While machining has been used to form the basic shapes of dentures and denture teeth, prior innovations fail to adequately address the aesthetics and function of the denture, particularly the aesthetics at and below the gum line. For example, in a traditional denture the denture teeth mimic the appearance of a natural tooth only above the gum line because traditional denture teeth adhere to a denture baseplate rather than extending into the baseplate with roots, as would real teeth. Traditional denture teeth are made in standard shapes using injection molding or pressure molding techniques. Anatomical roots are not incorporated in these teeth because of manufacturing difficulties. Currently, a dental technician may festoon root structures in the denture base and use different coloring techniques to paint the dental base to simulate the roots. This requires additional cost, delay, and expense and does not aesthetically mimic a natural tooth as completely as an anatomical root would. Thus there is a need for a denture having a more natural structure that will exhibit an improved aesthetic appearance.
Prior innovations also fail to adequately address the function of traditional dentures with traditional denture teeth. Dentures need to be balanced to avoid the patient's denture becoming loose or unstable during the protrusive and lateral movement of the mandible. This often requires grinding the occlusal surface of the denture teeth until the dentures remain in contact on at least three points throughout much of the movement of the mandible. Traditionally, a denture technician will set up the denture in an articulator and grind the teeth until the occlusive design of the denture is balanced. However, grinding the teeth will take away the enamel layer of the teeth, diminishing the aesthetic appearance of the teeth and functionally weakening the teeth. Thus there is a also need for a denture which is balanced, yet with unground occlusal surface (enamel) so that the denture has a more natural structure that will exhibit an improved aesthetic appearance and will not suffer from weakening of the enamel due to grinding.
Furthermore, in many dentures, a metal bar often sits beneath the denture base to enhance stability and strength. Often if the denture is implant supported, the denture is installed without the bar structure until such time as the patient has healed from the surgery enough so that the inflammation or swelling of the patient's soft tissue has receded to allow the bar structure to fit beneath the denture base. Then a modified denture must be reinstalled, with the bar structure. Furthermore, denture acrylics are often not strong enough to sustain bite forces, thus the base is often mounted on a bar to distribute the forces. This bar can be undesirable due to the associated bulk, cost, weight, and production delay and expense. Thus there is yet another need for a denture having a reinforcement structure but without the bulk, cost, weight, production delay and expense associated with the bar structure.
Accordingly, there remains a need for a denture that more closely simulates natural mouth structures, providing both structural and aesthetical improvements and which, in the case of implant-supported dentures, does not require a follow up procedure to insert a separate bar beneath the denture.